This research will develop new techniques for organic synthesis based on enzymes as catalysts. It will emphasize: 1) Synthesis of chiral synthons by kinetic resolutions employing lipases, esterases, fumarase, acylase, acetate kinase, lactate dehydrogenase and malic dehydrogenase. 2) Development of techniques for regeneration of important cofactors: coenzyme A, NAD, and 3'-phospho-5'-adenylyl sulfate (PAPS). 3) Synthesis of sugars, oligosaccharides, and polysaccharides using aldolase and complex enzyme-based schemes involving both Leloir pathways (for hyalauronic acid and glycosyl derivatives of N-acetylneuraminic acid) and non-Leloir pathways (for dextrans, glycogen, and analogs of these polymers). 4) Preparation of specific, small biochemically important molecules: N-acetylneuraminic acid, KDO, sphingosine, CoASH. 5) Exploration of techniques for assembling and controlling complex synthetic systems involving eight or more cooperating enzymes capable of performing both synthetic and cofactor-regenerating functions ("artificial metabolism").